Box with hinged lid

ABSTRACT

The invention relates to a box with a hinged lid wherein the lid is reliably closed by way of an enlarged collar section ( 20 ) as compared to conventional boxes with a hinged lid. The closure is even rendered more reliable by recesses on the insides of the lid that optionally are further provided with embossed sections.

RELATED APPLICATIONS

This application is a U.S. National Stage application of InternationalApplication No. PCT/EP02/01477, filed Feb. 13, 2002 and published inGerman, and which claims priority from German Application DE 101 06 549,filed Feb. 13, 2001.

The invention relates to a flip-top box, in particular for cigarettes,with a lid and box part, the rear wall of which is linked to the rearwall of the lid part. The box also has a collar with a collar front walland collar side walls and with a cut-out section in the collar frontwall, the collar being arranged on the inside of the box front wall andthe box side walls and projecting partly out of the box part.

Such flip-top or hinge-lid boxes are the most common cigarette boxesalongside soft-pack packs. In the standard form, these hinge-lid boxeshave a rectangular cross-section, i.e. the longitudinal edges areapproximately right-angled. More recently however, there have also beenincreasing numbers of flip-top boxes with chamfered longitudinal edges(i.e. an 8-cornered cross-section) or rounded-off longitudinal edges.With all these flip-top boxes, the problem arises that, in particularafter frequent opening and closing, the lid does not remainautomatically in the closed position, but opens somewhat. This leads toan increased loss of aroma and moreover tobacco crumbs for example canfall into the pockets of the consumer in undesired manner.

To solve this problem, the hinge-lid packs customary in the trade haveindents on the longitudinal edges of the collar.

This has the effect that when the collar is folded, the materialenclosed by the indents projects laterally like ears. Thus upon closureof the lid, an additional frictional resistance is produced whichensures a better closure of the lid. The disadvantage here, however, isthat with frequent opening and closing, in particular with boxes withrounded-off and chamfered longitudinal edges, the projecting collarparts are bent or folded and fit into the indent with the result thatthe additional friction is lost again.

EP 0 434 962 B1 provides a two-layer lid front wall to solve thisproblem. The inside of the lid front wall is provided with recesseswhich, upon closure of the lid, come into contact with rims remainingbeside the cur-out section of the collar front wall such that part ofthese rims come to lie between the inside and the outside of the lidfront wall. An increased friction between lid and collar and thus abetter closure of the lid also results from this.

U.S. Pat. No. 5,478,011 also operates with indents or recesses on theinside of the lid front wall in order to achieve as secure as possible aclosure of the lid. In addition, in this document, an embossed area onthe inside of the lid front wall is also described so that a cavityresults between outside and inside of the lid front wall. Thisfacilitates the insertion of the collar rims between outside and insideof the lid front wall.

A disadvantage in the solution proposals of EP 0 434 962 B1 and U.S.Pat. No. 5,478,011 is that, in addition to an increased material outlay,a more complicated production process with additional process steps,combined with the provision of additional indents or recesses, is alsonecessary.

The object of the present invention is therefore to provide a flip-topbox, in particular with chamfered or rounded-off longitudinal edges,with secure closure of the lid, which can be produced in the simplestpossible manner.

This object is achieved by a box made of foldable material such as forexample paper, cardboard, plastic, plastic film, plastic laminate,

-   -   with a box part, the box part having a box front wall, a box        rear wall, box side walls and a box base,    -   with a lid part, the lid part having a lid front wall, a lid        rear wall, lid side walls and a lid top side, and    -   with a collar, the collar having a collar front wall provided        with a cut-out section and collar side walls,    -   the lid part being linked with the lid rear wall on the box rear        wall,    -   the collar being arranged in the box part and    -   the collar front wall and as a rule also the collar side walls        projecting at least partly out of the box part,        characterized in that the rim of the collar front wall remaining        on the left and right next to the cut-out section is so narrow        that it projects forward due to the rigidity of the foldable        material, in particular in its upper area. In other words, as a        result of a simple broadening of the cut-out section in the        collar front wall and the thereby resulting projection of the        rims of the collar front wall, an increased friction between        these rims and the inside of the lid front wall is achieved with        the result that the lid is held essentially in the closed state.

In order to achieve the desired effect of an increased friction throughthe forward-projecting rims of the collar front wall, a small increasein the breadth of the cut-out section compared with customary cigaretteboxes is already sufficient, for example an increase of 3% or more, inparticular 4 to 15%, preferably 4 to 7%, particularly preferably 4 to 5and approximately 4%.

With a box customary in the trade (with a maximum breadth of the collarpart in the box of 5.6 cm) in which all longitudinal edges are roundedoff, this means in practice a broadening of the cut-out section byapprox. 1.5 mm. In other words the cut-out breadth at half height(mid-height calculated from the bottom edge of the cut-out section tothe maximum height of the cut-out section, which in customary cigaretteboxes is defined by the horizontally running top edges of the rims ofthe collar front wall or of the collar side walls) is approximately 3.25cm. If this breadth is increased at mid-height by 1.5 mm orapproximately 4.5% to 3.40 cm, the desired effect of a clearly increasedfriction already occurs. This effect is also already to be seen with acut-out section broadening of only approx. 3%, but becomes all the morepronounced with an increase in the cut-out section breadth or with areduction of the breadth of the laterally remaining rims, an upper limitof approx. 20% being set however by the overall breadth of the box.

The cut-out section broadening can also be given by the ratio of themid-height breadth of the cut-out section to the maximum breadth of thecollar part in the finished box. This is approximately 0.74 for flip-topboxes of the state of the art with rectangular longitudinal edges, andapproximately 0.69 with chamfered or round longitudinal edges. For theboxes according to the invention with rectangular longitudinal edges,this ratio is to be greater than 0.76, preferably 0.78 to 0.81, and forthe boxes according to the invention with chamfered or roundlongitudinal edges, greater than 0.71, preferably 0.72 to 0.73.

Preferably, one or more, in particular all the longitudinal edges oronly the two front longitudinal edges on the side of the opening of theflip-top boxes according to the invention are rounded off or chamferedbecause the remaining rim areas beside the cut-out section of the collarfront wall then project forward particularly markedly and thereforecontribute particularly well to the secure closure of the lid. With thecustomary flip-top boxes with essentially rectangular edges, this effectis not so strongly pronounced with the result that for these a greatercut-out section broadening, in particular of 5 to 10%, is preferred.

In order to achieve rounded-off or chamfered edges, the pre-cut sheetfrom which the cigarette box is produced is provided either with groovesor scoring lines at the areas forming the edges of the cigarette box.According to U.S. Pat. No. 4,955,531, the grooves can be produced in aform in which the pre-cut sheet is indented by a grooving unit at therelevant points. On the opposite side there is a groove channel intowhich the material of the pre-cut sheet can be pressed. In the case ofparallel-running grooves, a corrugated cross-section is producedaccording to the described process. An alternative to grooves arescoring lines. The thickness of the material forming the pack is herebyreduced using a scoring knife. For this purpose, the pre-cut sheet isplaced on a flat support and worked with a scoring knife with the resultthat, in addition to a compression, material can also be removed.Depending on the shape of the scoring knife, for example a v- oru-shaped cross-section is formed. As the support does not have channelsat points opposite the scoring knife, as in the production of grooves,but rather a flat surface, a reduction in thickness results and not, asin the case of the grooves, a deformation without a reduction inthickness. The extent of the reduction in thickness depends on thematerial used, but as a rule will be 10 to 80% of the overall thickness,preferably 20 to 70%, quite particularly preferably 40 to 50%. Thescoring lines are preferably located on the side of the pre-cut sheetwhich forms the inside in the finished box. This has the advantage of amore attractive optical appearance of the finished box. The scoringlines and grooves preferably extend over the whole length of the boxwith the result that completely round or chamfered longitudinal edgesare obtained.

When the thus-worked pre-cut sheer is folded up, the round (in the caseof several grooves or scoring lines per fold area) or chamfered (in thecase of two grooves or scoring lines per fold area) edges of thecigarette pack then automatically form along the grooves or scoringlines. The extent and the type of rounding can be fixed by the number ofgrooves or scoring lines and their distance from one another. 6 to 8, inparticular 7, grooves or scoring lines per fold area which are locatedat a distance of approximately 1 mm from one another are preferred. Uponfolding, a box with round edges results; the radius of the rounding thenapproximately corresponds to that of a cigarette customary in the trade.2 grooves or scoring lines per fold area which are located at a distanceof 6 to 8 mm, in particular approximately 7 mm, from each ocher are alsopreferred. Upon folding a box with chamfered (or bevelled) edges thenresults.

The boxes can be produced from the customary materials for cigaretteboxes such as e.g. paper, cardboard, plastic, plastic film or plasticlaminate or one of the named materials with an additional metal ormetal-oxide coating.

Paper or cardboard are preferably used, shortgrain paper or shortgraincardboard are particularly preferred as foldable material for the lidand the box part and also the collar. In the case of paper or cardboardproduction, the product-forming material is placed on a fast-movingbelt. This has the effect that the long fibres in the materialpreferably orient themselves in longitudinal direction. Depending onwhether the pre-cut sheet is later cut along or across the finishedmaterial web, the long fibres in the pre-cut sheet are arranged acrossthe longitudinal axis of the pre-cut sheet (shortgrain) or longitudinalto the longitudinal axis of the pre-cut sheet (longgrain). The result ofthe orientation of the fibres across the longitudinal direction of theshortgrain pre-cut sheet is a good flexibility about the transverseaxis, but a poor flexibility about the longitudinal axis. The elasticrestoring forces for the lateral gluing are therefore stronger than withlonggrain pre-cut sheets in which, due to the transposed position of thelong fibres in the material, the conditions are exactly the opposite. Onthe other hand however, shortgrain precut sheets are preferably used forflip-top boxes, as they clearly favour the stability of the lid (nocrooked closures, no easy tearing-off of the lid), the rigidity of thepack as a result of a higher stability in the transverse direction andthe flat position of the pack, i.e. as small a curvature of the pack aspossible, compared with the use of longgrain materials.

For the boxes according to the invention therefore, the use ofshortgrain materials is preferred because on the one hand these producethe named positive properties for the lid and box part such as stabilityof the lid and rigidity and flat position of the pack, on the other handthe projection of the rims of the collar front wall is still furtherincreased by the elastic restoring forces increased with shortgrainmaterials due to the orientation of the long fibres across thelongitudinal axis of the collar.

The use of shortgrain materials for the production of flip-top boxeswith chamfered or rounded-off longitudinal edges is somewhat problematicbecause on the one hand (as discussed above) the elastic restoringforces are increased, on the ocher hand the lateral surfaces for gluingare smaller than with normal boxes as a result of the chamfered orrounded-off edges. The residence times upon gluing must therefore beincreased, which leads to a slowing-down of production.

In order to avoid this problem, it is preferred with the boxes accordingto the invention with rounded-off or chamfered longitudinal edges thatthe fold lines which lead to the chamfered or rounded-off edge areformed by scoring lines in the case of the lid and box part. Through thescoring lines, unlike grooves, the elastic restoring forces aresurprisingly clearly reduced with the result that the production of theboxes according to the invention can also be carried out problem-freeand swiftly with shortgrain materials without problems arising with thelateral closure of the boxes as a result of the smaller available gluingsurface.

Unlike the box and lid part, it is however preferred with the boxesaccording to the invention with rounded-off or chamfered edges that theelastic restoring forces of the collar part are not reduced. It istherefore preferred that the fold lines of the collar which produce thechamfering or rounding-off between collar front wall or collar sidewalls are formed by grooves because the outer rims of the collar frontwall then project more markedly forward and the friction with the insideof the lid in closed state is increased.

For the collar part, in addition to the shortgrain materials described,the longgrain materials usually used for collars can also be usedhowever, preferably again in combination with grooves in order to reducethe elastic restoring forces as little as possible and to ensure aseffective as possible a projection of the collar front wall rims.

To improve the closure of the lid still further, the inside of the lidfront wall can be formed by a strengthening field with at least one,preferably two recess(es) which is/are shaped such that upon closure ofthe lid part it/they interacts/interact with the edge(s) of the collarrim(s) so that in the closed state of the box at least a part of thecollar rim/rims comes/come to rest between the outside of the lid frontwall and the strengthening field.

In order to ensure that the interaction between the recess and thecollar rim runs problem-free, the recesses are essentially v-shaped,their edges curved (so that the collar edges can easily slide under thestrengthening field), the deepest point of the recesses lies roughly atmid-height of the strengthening field and the recesses extend startingat the top edge of the strengthening field over approx. 50 to 90%, inparticular 60 to 70%, of the height of this strengthening field (whichin turn facilitates the insertion of the collar rims betweenstrengthening field and lid front wall outside).

In order to further facilitate the insertion of the collar rims, one orpreferably both top corners of the strengthening field are provided withan embossed area which preferably has the thickness of the foldablematerial and extends over the whole top corner to the edge of the recessand the top edge of the strengthening field.

The boxes according to the invention are produced in known manner frompre-cut sheets and separate collar parts, i.e. the pre-cut sheets andthe collar parts are taken off widths of pre-cut sheet material whichare stored on rolls and optionally printed, preferably as shortgrainpre-cut sheets. This is usually followed by a step in which the pre-cutsheets and the collar parts are worked by a scoring knife or a groovingunit in the described manner and at the same time punched and/or cut andoptionally embossed. In this step, the broadened collar cut-out sectionis also retained, which is realizable in terms of process engineeringsimply by appropriate adaptation of the cutting or punching tool.Provided the pre-cut sheets used for the production of the boxesaccording to the invention have an embossed area up to the rim of thepre-cut sheet, for manufacturing reasons, the embossing must be carriedout first and then the pre-cut sheet cut out or stamped out in aseparate step. By customary folding and gluing of the pre-cut sheets atthe side surfaces with simultaneous partial insertion and gluing of thecollar to the box front wall and/or the box side walls, the finishedcigarette box, which usually contains a cigarette group wrapped in aninner liner, is then obtained by machine.

The invention will be explained in more detail in the following using anembodiment. There are shown in:

FIG. 1 a collar pre-cut sheet 10,

FIG. 2 a pre-cut sheet 100 for the box and lid part and

FIG. 3 a further pre-cut sheet 100 with slightly modified strengtheningfield 30.

FIG. 1 shows a pre-cut sheet made of shortgrain paper or cardboard for acollar 10 with collar front wall 12 and collar side walls 14. Groovelines 15 between collar front wall 12 and the two collar side walls 14can also be seen. Seven groove lines 15 which run parallel to oneanother at a distance of approximately 1 mm are provided in total foreach fold area. The total fold area is therefore 6 mm wide.

The collar 10 also has the rim areas 16 which are limited by the edges18 on one side and the fold areas with the grooves 15 on the other side.The collar 10 also has a cut-out section 20 which has a mid-height ofapprox. 34 mm here. In a box according to the invention which containsthe collar shown here, the rims 16 would therefore project forward andthus essentially effect a secure closure of the lid.

FIG. 2 shows a pre-cut sheet 100 made of shortgrain paper or cardboardfor the production of a cigarette box. There can be seen the customaryfields, i.e. main surface fields 40, 42, 44 and 46 with thecorresponding side-surface fields 41, 43, 45 and 47 which, in thefinished cigarette box, form the box front wall, the box rear wall, thelid front wall and the lid rear wall as well as the side walls of thelid and box part. Also to be seen are the base field 48 and the top sidefield 50 which, in the finished box, correspond to the box base and thelid top side. The pre-cut sheet 100 of FIG. 2 has 7 scoring lines 52running essentially parallel at a distance of approx. 1 mm. Further foldlines alongside the scoring lines 52 are drawn in dotted lines in FIG. 2and numbered 54. The pre-cut sheet also has two indents 56 and alsoside-surface field end tabs 58 and 59. The strengthening field 30 whichhas an approximately v-shaped recess 32 on both sides joins above withthe main surface field 46. Each of the two top corners 34 of thestrengthening field 30 has an embossed area 36 which extends completelyfrom the top edge 38 of the strengthening field 30 to the deepest pointof the recesses 32.

To produce the cigarette box, the side-surface fields 41 can firstly befolded upwards by 90° and the side-surface field end tabs 58 locatedthere folded inwards also by 90°. Then the bottom part of the pre-cutsheet 100 is folded upwards by 90° with the base surface 48 and thefirst main surface field 40, as a result of which the side-surface fieldend tabs 58 come into contact with the base field 48 and are glued. Ifthe first main surface field 40 is folded in further (by 90°), theside-surface fields 43 and 41 come to lie on top of one another and canbe glued, with the result that the box part is finished. The lid part isproduced in similar manner, i.e. the side-surface field end tabs 59 areglued to the top side field 50. The strengthening field 30 is gluedinwardly onto the fourth main surface field 46 and thereupon theside-surface fields 45 and 47 glued together. During this productionprocess or subsequently, the collar 10 shown in FIG. 1 for example canbe arranged on the inside of the first main surface field 40 such that apart of the collar projects out of the box part. The collar can beconnected to the lid front wall, i.e. the first main surface field 40,as well as optionally the corresponding side-surface fields, by gluing.

The strengthening field 30 with the two lateral recesses 32 is thenlocated on the lid front wall inside of the finished box. Upon closureof the box, due to the curved rim pattern of the recesses 32, the edge18 of the collar rims 16, facilitated by the embossed areas 36, isguided between strengthening field 30 and fourth main surface field 46and held there by friction.

The embossed areas 36 can also be attached along the cutting lines 39 asshown in FIG. 3.

1. Box made of foldable material with a box part, the box part having abox front wall, a box rear wall, box side walls and a box base, with alid part, the lid part having a lid front wall, a lid rear wall, lidside walls and a lid top side, and with a collar, the collar having acollar front wall provided with a cut-out section and collar side walls,the lid part being linked with the lid rear wall on the box rear wall,the collar being arranged in the box part, and the collar front wallprojecting at least partly out of the box part, wherein the rim of thecollar front wall remaining on the left and right next to the cut-outsection is so narrow that it projects forward due to the rigidity of thefoldable material, in at least its upper area, wherein the inside of thelid front wall is formed by a strengthening field with at least onerecess which is shaped such that upon closure of the lid part the atleast one recess interacts with the edge of a collar rim so that in theclosed state of the box at least a part of the collar rim comes to restbetween the outside of the lid front wall and the strengthening field,wherein the at least one recess is essentially v-shaped, the edges ofthe at least one recess are curved, and the deepest point of at leastone recess lies roughly at mid-height of the strengthening field.
 2. Boxaccording to claim 1, wherein the lid is held essentially in the closedstate by the friction between the forward-projecting rim of the collarfront wall and the inside of the lid front wall.
 3. Box according toclaim 1, wherein one or more of the longitudinal edges of the box part,of the lid part and of the collar is rounded off or chamfered.
 4. Boxaccording to claim 1, wherein the foldable material is paper orcardboard.
 5. Box according to claim 4, wherein the foldable material isshortgrain paper or shortgrain cardboard.
 6. Box according to claim 5,wherein one or more of the longitudinal edges of the box are rounded offor chamfered and the rounding or chamfering of the longitudinal edges ofthe box and lid parts is formed by scoring lines and the rounding or thechamfering of the collar by grooves.
 7. Box according to claim 1,wherein the at least one recess extends from the top edge of thestrengthening field over approximately 50 to 90% of the height of thestrengthening field.
 8. Box according to claim 1, wherein at least oneof the top corners of the strengthening field is provided with anembossed area.
 9. Box according to claim 8, wherein the embossed areaextends inwards from the top edge of the strengthening field toward acentral region of the strengthening field and extends inwards from thetop edge of the at least one recess toward the central region of thestrengthening field.
 10. Box according to claim 8, wherein the embossedarea approximately corresponds to the thickness of the foldablematerial.
 11. Box according to claim 1, wherein the box is a cigarettepackage.
 12. Box according to claim 1, wherein the at least one recessextends from the top edge of the strengthening field over approximately60 to 70% of the height of the strengthening field.
 13. Box made offoldable material with a box part, the box part having a box front wall,a box rear wall, box side walls and a box base, with a lid part, the lidpart having a lid front wall, a lid rear wall, lid side walls and a lidtop side, and with a collar, the collar having a collar front wallprovided with a cut-out section and collar side walls, the lid partbeing linked with the lid rear wall on the box rear wall, the collarbeing arranged in the box part, and the collar front wall projecting atleast partly out of the box part, wherein the rim of the collar frontwall remaining on the left and right next to the cut-out section is sonarrow that it projects forward due to the rigidity of the foldablematerial, in at least its upper area, wherein the inside of the lidfront wall is formed by a strengthening field with at least one recesswhich is shaped such that upon closure of the lid part it interacts withthe edge of a collar rim so that in the closed state of the box at leasta part of the collar rim comes to rest between the outside of the lidfront wall and the strengthening field, wherein at least one top cornerof the strengthening field is provided with an embossed area, whereinthe at least one recess is essentially v-shaped, the edges of the atleast one recess is curved, the deepest point of the at least one recesslies roughly at mid-height of the strengthening field, and the at leastone recess extends from the top edge of the strengthening field overapproximately 50 to 90% of the height of the strengthening field. 14.Box according to claim 13, wherein the at least one recess comprises atleast two recesses.